1. Field of the Invention
This invention relates to an electric connection box which has electrical parts mounted thereon, and is mounted on a vehicle or the like.
2. Related Art
An electric connection box and a battery are received within an engine room, for example, of an automobile in which a power source is hybridized by the addition of a motor to an engine, and the electric connection box and the battery are electrically connected together by a power cable.
The electric connection box has a generally box-like shape as a whole, and as shown in FIG. 5, a bus bar 5 of an elongate rectangular plate-like shape, a current sensor 3 (which is to be electrically connected to the bus bar 5), etc., are sequentially mounted in a fitted manner on a synthetic resin-made lower cover 1, and then a synthetic resin-made upper cover 9 is put on the lower cover to cover these parts. The lower cover 1 and the upper cover 9 are fixed or fastened together by bolts 2. Various electrical parts, including a main contactor 11, a pre-charge contactor 10 and a resistor 12, are mounted in their respective predetermined positions on the upper casing 9.
The bus bar 5 is made of an electrically-conductive metal sheet, and one end portion (in a longitudinal direction) of the bus bar 5 is bent upwardly into a generally L-shape to provide a minus-side input terminal 6a and a plus-side input terminal 6b, and the plus-side input terminal 6b passes through a central portion of a Hall element 3a provided at the current sensor 3. A minus-side output terminal 8a and a plus-side output terminal 8b are formed at the other end of the bus bar 5. Such a conventional technique is described, for example, in the following JP-A-2004-080966.
The basic constitution and measurement principle of the current sensor are disclosed in JP-A-2001-66328.
In the above electric connection box, to positively mount the electrical parts in their respective predetermined positions is extremely important for obtaining stable characteristics. Particularly when mounting the current sensor 3 on the lower cover 1, there is encountered a situation in which a center axis of the Hall element 3a of the current sensor 3 is deviated from a center axis of the plus-side input terminal 6b of the bus bar 5 due to an error in the mounting of the current sensor 3 relative to the lower cover 1 or other factor, so that a sensing performance of the current sensor 3 is degraded.
And besides, the electric connection box is mounted at a place where severe vibrations develop during the driving of an engine and the travel of the vehicle, and therefore the current sensor 3 is displaced relative to the bus bar 5 when a holding force of the lower cover 1 for holding the current sensor 3 is low. As a result, the sensing performance of the current sensor 3 is lowered, and the reliability of the product is adversely affected.
Furthermore, the current sensor 3 is formed as a part separate from the lower cover 1, and at a later stage or step, this current sensor is mounted on the lower cover 1. Therefore, the number of the component parts as well as time and labor required for the assembling operation, increases, and the achievement of a space-saving design is prevented.